Surrey County Council plans to close a large section of the southbound side of Reigate Hill (A217) for up to 14 weeks from Monday 7 September 2020.
The closure will run from the M25 junction 8 down the hill but will stop to the north of the petrol station and pub.
The southbound side will be fully closed, 24 hours a day, but the northbound side will remain open.
Repairs will be carried out to a 240m retaining wall that runs along the A217, and to the vehicle barrier that sits on it.
The county council has said that it will work with the contractor to try to shorten the work.
A signed diversion route will be in place.
People will be able to access the Reigate Hill café, and car park, using Wray Lane and Gatton Bottom.